The optimal infusion technique (continuous rate vs. intermittent bolus) for peripheral nerve blocks has not been established. To our knowledge, this is the first study to compare the efficacy of an automated intermittent bolus technique to a continuous rate of infusion of local anesthetic in femoral nerve catheters. We hypothesized that the intermittent bolus technique would provide enhanced analgesia compared to a continuous infusion rate as assessed by intravenous patient-controlled analgesia (IV-PCA) hydromorphone consumption and visual analog scale (VAS) pain scores.